In recent years, owing to operation speed increase of personal computers, improvement of network infrastructure and increase of capacity as well as price reduction of data storage, there is expanding opportunities that information such as images and documents conventionally provided as printed matters printed on paper are obtained as more convenient electronic data and the electronic data is browsed.
To brows such electronic data, conventionally there have been mainly used liquid crystal displays, CRTs, and recently luminescent type display such as organic EL displays. However, in case the electronic data is document data in particular, the document data has to be gazed for relatively a long time. As shortcomings of the luminescent type display in general, there are known ocular fatigue due to flicker, inconvenience of portability, a restricted posture of reading and large consumption of electric power when reading long time.
As a display method to resolve the above shortcomings, an electrochemical display method is known. For example, an electro deposition method (hereinafter abbreviated to ED) using dissolution deposition of metal or metallic salt is known (for example, refer to Patent Documents 1 and 2).
The display element of the ED method can be driven by a low voltage of 3V or less which can be realized with a simple cell structure and it has a feature that the display quality is superior (paper-like bright white and tight black).
To drive the electrochemical display element of such as ED method a predetermined voltage exceeding a threshold value is applied at both ends of the electrochemical display element for a predetermined time. The display conditions can be controlled by the voltage and time.
However, in the display apparatus having the plurality of the electrochemical display elements arranged in the matrix state, a current to drive the display apparatus is large. In particular, in case of the ED method, since dissolution deposition of metal or metallic salt is utilized, a large current is drawn at an initial stage of applying the voltage and a peak voltage to drive the display apparatus becomes very large. To address the large current, a power source circuitry having large current capacity has to be prepared, which causes cost increase.
Also, since bus wiring common for the plurality of the electrochemical display elements and common electrodes such as transparent electrodes have resistance to some extent in general, the voltage decreases as the elements recede from the power applying source, thus there is a problem that unevenness of display occurs.
To solve the above problem, there is suggested a method to make erasing and writing of the image uniform across an entire screen by setting a magnitude and an application time of a selection voltage to be applied to the counter electrodes in accordance with the distances from the drive section of the transparent electrodes (refer to Patent Document 3).